Saturday, September 02, 2017

Before & After Harvey

This week the Washington Post wondered what would happen if you dropped a huge volume of water on other locations in the United States. It has put together a number of mapped visualizations which imagine the effect historic levels of flooding could have on other cities. Meanwhile Esri has used NOAA aerial surveys to show images of Houston before and after Hurricane Harvey.

The Washington Post's map What the Harvey deluge would look like where you live allows you to enter any location to view a visualization of the effect a 51.88-inch deluge of rain might have if it fell on that location. The map places a number of blue circles around your searched location. You can click on these circles to view the depth of flooding you could expect at that point based on its elevation.

The Washington Post also created a number of more realistic looking maps visualizing what the levels of flooding in Houston might look like in other cities. In What 500-year flooding could look like around five cities the newspaper has five interactive maps showing how Harris Co, New Orleans, Tampa Bay, Miami-Dade Co. and New York might look if they experienced "a once in 500-year flood". These five maps are based on population data from the 2010 Census and FEMA National Flood Hazard maps.

Of course we don't have to imagine what the effect a "once in 500 year flood" might have on a city. We can see the effect it has had on Houston. Esri has released an interactive map which allows you to compare side-by-side aerial imagery of Houston taken before and after Hurricane Harvey.